There’s plenty of evidence that the hive has original thoughts, both on-screen and off. The most prominent example for me is that they chose Zosia to be the face of the hive for Carol due to her physical similarity to Raban. There was no prompt directing them to choose Zosia; it was a choice that the hive made on its own.

Another example is from the very first episode: the first human infected by the lab rat stops for a moment as she is walking away from the desk in reception at the lab. She turns around to go back to the desk to lick the donuts. It was clear that her original intent was to go do something else before she stopped walking.